Fortify the antioxidant defenses for your cardiovascular system and your whole body with the free radical fighting power of Swanson Premium Quercetin. An antioxidant flavonoid found in onions, apples, green tea and other plant sources, quercetin delivers valuable free- radical protection for blood vessels and other vital tissues throughout the body. Our high potency capsules are an excellent, economical way to incorporate this cell defender into your wellness plan.